Metastatic Castration-Sensitive Prostate Cancer Treatment

Primary Treatment Recommendations

• The National Comprehensive Cancer Network recommends apalutamide 240 mg daily plus androgen deprivation therapy (ADT) as a Category 1 treatment option that significantly improves both radiographic progression-free survival and overall survival for patients with metastatic castration-sensitive prostate cancer 1, 2

Key Trial Results

• The TITAN trial demonstrated that apalutamide plus ADT improves radiographic progression-free survival (68.2% vs 47.5% at 24 months, HR 0.48; 95% CI 0.39-0.60; P<0.001) and overall survival (82.4% vs 73.5% at 24 months, HR 0.67; 95% CI 0.51-0.89; P=0.005) compared to placebo plus ADT 1, 2
• The TITAN trial also showed that apalutamide plus ADT improves median overall survival (not reached vs 52.2 months, HR 0.65; 95% CI 0.53-0.79; P<0.001) compared to placebo plus ADT 1, 2

Patient Selection Criteria

• The American Society of Clinical Oncology recommends offering apalutamide plus ADT to patients with newly diagnosed metastatic disease, relapsed metastatic disease after prior local therapy, and all disease volumes (both high-volume and low-volume disease) 3, 4
• The National Comprehensive Cancer Network recommends considering apalutamide plus ADT for patients stratified by Gleason score at diagnosis 1, 2

Dosing Regimen

• The recommended dosing regimen for apalutamide is 240 mg orally once daily, with continuous LHRH agonist/antagonist or surgical castration as ADT 1, 2, 5

Safety Profile and Monitoring

• Common adverse events associated with apalutamide include rash, hypothyroidism, and ischemic heart disease, which require monitoring 1, 2
• Grade 3-4 adverse events were similar between treatment groups (approximately 24-26%), and health-related quality of life was maintained during treatment 1, 2, 3

Clinical Practice Integration

• Apalutamide is one of three second-generation antiandrogens with proven survival benefit in metastatic castration-sensitive prostate cancer, along with enzalutamide and abiraterone, all of which are Category 1 recommendations 1, 2, 5
• Selection among these options should be guided by cost and patient-specific tolerability 3, 5

Common Pitfalls to Avoid

• Delaying treatment until symptoms develop should be avoided, as early initiation with metastatic disease improves survival 1, 2
• First-generation antiandrogens should not be used as alternatives to second-generation agents, as they provide inferior survival outcomes 1, 2
• Assuming lack of benefit in older patients is incorrect, as the TITAN trial included patients across age ranges with consistent benefit 1, 2
• Ensuring castrate testosterone levels are maintained throughout treatment with ADT monitoring is crucial 1, 2

First-Line Treatment Options for Metastatic Castration-Sensitive Prostate Cancer (mCSPC)

Standard Treatment Combinations with Survival Data

• The National Comprehensive Cancer Network recommends enzalutamide 160 mg orally once daily for the treatment of metastatic castration-sensitive prostate cancer, with a study design of multiple phase III randomized controlled trials 6
• The dosing of abiraterone is 1000 mg daily plus prednisone 5 mg twice daily, with a study design of phase III randomized controlled trials, and the National Comprehensive Cancer Network recommends its use for the treatment of metastatic castration-sensitive prostate cancer 6
• The National Comprehensive Cancer Network recommends docetaxel 75 mg/m² IV every 3 weeks for up to 6 cycles for the treatment of metastatic castration-sensitive prostate cancer, with a study design of phase III randomized controlled trials, and notes that acute toxicity includes neutropenia, febrile neutropenia, fatigue, and neuropathy 7

Bone Health and Supportive Care

• The National Comprehensive Cancer Network recommends zoledronic acid 4 mg IV annually or alendronate 70 mg PO weekly for the treatment of bone health in patients with metastatic castration-sensitive prostate cancer, when fracture risk warrants treatment 7
• The National Comprehensive Cancer Network recommends supplemental calcium 1200 mg daily and vitamin D3 800-1000 IU daily for all men over 50 years on androgen deprivation therapy 7

Treatment Selection Algorithm

• The National Comprehensive Cancer Network recommends verifying castrate testosterone levels are achieved and maintained throughout treatment, and continuing androgen deprivation therapy indefinitely regardless of additional therapies 6
• The National Comprehensive Cancer Network recommends that selection among androgen receptor pathway inhibitors should be guided by cost and patient-specific tolerability 6

Subsequent Therapy After Progression

• The National Comprehensive Cancer Network recommends that after progression on first-line androgen receptor pathway inhibitor plus androgen deprivation therapy, docetaxel chemotherapy becomes the preferred next option due to cross-resistance between androgen receptor pathway inhibitors 6
• The National Comprehensive Cancer Network recommends continuing androgen deprivation therapy throughout all subsequent lines of therapy 6

First‑Line Management of Metastatic Castration‑Sensitive Prostate Cancer with Low PSA

Treatment Initiation

• Initiate androgen deprivation therapy (ADT) together with a second‑generation androgen‑receptor pathway inhibitor (abiraterone, enzalutamide, or apalutamide) in all patients with metastatic castration‑sensitive prostate cancer, irrespective of PSA level, because these combinations improve overall survival and progression‑free survival across disease volumes. Strong (Category 1) recommendation. [8][9]

Choice of Androgen‑Receptor Pathway Inhibitor

• Enzalutamide 160 mg daily plus ADT – recommended with high‑quality evidence for both de novo and recurrent metastatic disease. Strong recommendation. [8][9]
• Abiraterone 1 g daily plus prednisone 5 mg daily and ADT – receives a strong recommendation for patients with high‑risk disease (based on the LATITUDE trial) and a moderate recommendation for low‑risk disease (based on the STAMPEDE trial). [8][9]

Disease‑Volume Stratification (PSA‑Independent)

• High‑volume disease (visceral metastases or ≥ 4 bone lesions with at least one outside the axial skeleton) – all three agents (abiraterone, enzalutamide, apalutamide) have strong evidence supporting their use. Strong recommendation. 9
• Low‑volume disease – abiraterone is supported by moderate‑strength evidence, whereas apalutamide and enzalutamide retain strong evidence across all disease volumes. Strong recommendation for apalutamide and enzalutamide; moderate for abiraterone. [8][9]